Valve seats, valve assemblies, and related methods

ABSTRACT

Valve seats may include an insert and an outer housing. The insert may comprise a first material and the outer housing may comprise a second material. The second material of the outer housing may exhibit a hardness that is greater than a hardness of the first material of the insert. Valve assemblies and related method may include valve seats.

TECHNICAL FIELD

The present disclosure relates generally to valve seats, and, moreparticularly, to valve seats including multiple materials, valveassemblies including valve seats including multiple materials andrelated methods.

BACKGROUND

Many valve types have been employed for stopping and controlling theflow of fluids in a pipe or other flow path. Each of these valves offerscertain advantages while suffering from other disadvantages. Some valvetypes include plug valves, ball valves, stop or globe valves, anglevalves, butterfly valves, and gate valves.

Ball valves comprise a rotatable ball having a bore therethroughcorresponding to the fluid flow path together with one or more seats forsealing with the ball surface. Typical ball valves have a valve body anda valve member (e.g., a ball) operatively connected to the valve body byan upstream and a downstream seal. The valve body defines a flow passagehaving an upstream flow-through end (e.g., leading end), a downstreamflow-through end (e.g., trailing end), and a valve receiving chamberlocated between the upstream and downstream flow-through ends of theflow passage. The valve member is located within the valve receivingchamber, and includes a throughbore that allows passage of fluid throughthe valve member. The seals or seats, in conjunction with the valvemember and the valve receiving chamber, define a cavity around the valvemember. To prevent leakage of the valve, the seals or seats are pressedagainst the valve member with a given or fixed sealing pressure based,at least in part, on the maximum pressure environment in which the valvemay be installed.

The valve member is coupled to an actuator via a valve stem, which isselectively rotatable to rotate the valve member within the valvereceiving chamber, between a fully open position and a fully closedposition. Generally, in a two way valve, the fully open position occurswhen the throughbore is aligned with the flow passage at zero degrees ofrotation from a centerline of the flow passage and the fully closedposition occurs at ninety degrees of rotation of the valve member fromthe centerline.

The valve member ball is contained within the valve body between twovalve seats with physical compression applied to the seats duringassembly, such that the seats bear into the ball with force. In suchdesigns, the valve seats act as a seal at the point at which they bearonto the ball, and as a seal at points at which they bear against thevalve body. The valve seats also act as a spring to maintain the sealingforce during operation of the valve. The “off” position usuallycorresponds to a position of the ball wherein the conduit is at rightangles to the valve body passageway. However, lesser angulardisplacements may result in an “off” or partially “off” condition,depending upon the geometry of the valve components. The full “on”position is typified by the ball conduit being coaxially aligned withthe fluid passageway of the valve body. A conventional ball valveprovides varying degrees of flow restriction based upon the degree ofalignment of the ball conduit with the valve body passageway. Thus, fora given pressure, flow is controlled by varying the degree of alignmentof the ball conduit with the valve body passageway.

During the life of the ball valve, switching the ball between the “on”and “off” positions subjects the valve seats to thermal cycling, whichcan damage the valve seats and cause the seats to experience “creep,”which degrades the seal and causes leakage within the ball valveassembly. Valve seats made of softer, more elastic materials requireless compressive force to seal the ball; however, such softer, moreelastic materials are more susceptible to creep, which may occur rapidlyat elevated temperatures. To compensate, valve seats are oftenconfigured to provide a maximum physical compression against the ball,wherein the sealing force may be maintained even if some thermaldegradation or creep occurs. However, such compressive forces requiremore torque to operate the ball valve.

BRIEF SUMMARY

Various embodiments of the present disclosure comprise a valve seatincluding an insert and an outer housing. The insert may comprise afirst polymer material. The insert may be configured to be positionedproximate a valve member and to contact the valve member. The insert maydefine a portion of a seal between the valve member and a valve body inwhich the valve member is positioned. The outer housing may comprise asecond polymer material. At least a portion of the insert may bepositioned within the outer housing. The outer housing may be configuredto be positioned between the insert and the valve body to define anotherportion of the seal between the valve member and the valve body. Thesecond polymer material of the outer housing may exhibit a hardness thatis greater than a hardness of the first polymer material of the insert.

Another embodiment of the present disclosure may comprise a valveassembly including a valve body, a valve member, and at least one valveseat. The valve body may include at least one port. The valve member maybe positioned within the valve body. The valve member may be configuredto selectively enable fluid to pass through the at least one port in thevalve body. The at least one valve seat may include a seat member and asupport member. The seat member may comprise a polymer material. Theseat member may be positioned adjacent to the valve member and beconfigured to seal against the valve member. The support member maycomprise another polymer material. The support member may be positionedbetween the seat member and the valve body and configured to sealagainst the valve body.

Another embodiment of the present disclosure may include a method ofproviding a seal in a ball valve. The method may include positioning afirst section of a seat comprising a first polymer material adjacent toa movable ball of the ball valve. The method may also includepositioning a second section of the seat comprising a second polymermaterial adjacent to a body of the ball valve. The movable ball may beforced into the seat to form a seal between the movable ball and thevalve body with the seat.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming what are regarded as embodiments of the presentdisclosure, various features and advantages of embodiments of thedisclosure may be more readily ascertained from the followingdescription of example embodiments of the disclosure when read inconjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional side view of a valve including one or morevalve seats in a closed position in accordance with an embodiment of thedisclosure;

FIG. 2 is a cross-sectional side view of the valve including one or morevalve seats of FIG. 1 in an open position;

FIG. 3 illustrates an isometric view of a valve seat according to anembodiment of the present disclosure;

FIG. 4 illustrates an exploded isometric view of a valve seat accordingto an embodiment of the present disclosure;

FIG. 5 illustrates an enlarged cross-sectional view of a valve seataccording to an embodiment of the present disclosure;

FIG. 6 illustrates an enlarged cross-sectional view of a valve seataccording to an embodiment of the present disclosure; and

FIG. 7 illustrates an enlarged cross-sectional view of a valve seataccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The illustrations presented herein are not meant to be actual views ofany particular fluid exchanger or component thereof, but are merelyidealized representations employed to describe illustrative embodiments.The drawings are not necessarily to scale. Elements common betweenfigures may retain the same numerical designation.

As used herein, relational terms, such as “first,” “second,” “top,”“bottom,” etc., are generally used for clarity and convenience inunderstanding the disclosure and accompanying drawings and do notconnote or depend on any specific preference, orientation, or order,except where the context clearly indicates otherwise.

As used herein, the term “and/or” means and includes any and allcombinations of one or more of the associated listed items.

As used herein, the term “substantially” or “about” in reference to agiven parameter means and includes to a degree that one skilled in theart would understand that the given parameter, property, or condition ismet with a small degree of variance, such as within acceptablemanufacturing tolerances. For example, a parameter that is substantiallymet may be at least 90% met, at least 95% met, at least 99% met, or even100% met.

As used herein, the term “fluid” may mean and include fluids of any typeand composition. Fluids may take a liquid form, a gaseous form, orcombinations thereof, and, in some instances, may include some solidmaterial.

Embodiments of the present disclosure may be utilized to control fluidflow in a system operated at normal environmental conditions and/or inhigh pressure and/or high temperature systems. In some embodiments, suchsystems may include industrial applications (e.g., power plants,processing systems, mineral extraction, etc.), vehicles (e.g., ships,tankers, submarines, locomotives, etc.), or control systems (e.g.,hydraulic systems, pneumatic systems, etc.).

Valve assemblies may include a valve member, such as a ball, containedin a valve body between two valve seats with physical compressionapplied to the seats during assembly such that the seats bear into theball with force. In such designs, the valve seats act as a seal at thepoint at which they bear onto the ball. The valve seats also act as aseal at points at which they bear against the valve body. The valveseats also act as a biasing force or spring to maintain the sealingforce during operation of the valve. This design may be problematic inthat softer, more elastic materials, which require less compressiveforce to form a seal against the ball, are less resilient to thermalstressing over the life of the valve. Moreover, softer, more elasticmaterials are susceptible to deformation, such as higher rates of creep,at any given temperature, and are prone to rapid rates of creep atelevated temperatures. An example of a common material used for valveseats that is susceptible to such problems is polytetrafluoroethylene(PTFE). Thermal stressing and creep can degrade the seal against theball valve, and result in leakage, particularly when the ball isswitched between the open and closed positions.

Further, valves may be utilized to control fluid flow in high pressureand/or high temperature systems may be exposed to relatively largeforces associated both with the pressure and impact from fluid flow(e.g., changes in fluid flow) that are absorbed by the valve seats whenthe valve is closed, opened, or moving between the open and closedpositions.

In order to avoid some of the problems with relatively softer seats,seats may be formed from higher strength materials that can withstandhigher loads resulting from high pressure or shock and generally higheroperating temperatures. Such higher strength seats may present thedisadvantage of requiring a higher sealing force combined with theirhigher frictional coefficient, in comparison to relatively softer seatmaterials, resulting in a significantly higher torque being required tooperate the valve. For example, such high strength materials may createhigher friction between the valve seats and the valve member than therelatively lower strength valve seat materials. The increased frictionmay require increased amounts of torque to operate the valve. Highpressure systems may also increase the amount of torque required tooperate the valve. The combined effect of the increased friction and theincreased pressure may result in large amounts of required torque. Largeamounts of torque may require larger, cumbersome, and/or more expensiveactuation devices (e.g., electronic or manually operated actuators).

Embodiments of the present disclosure may provide a valve seat (e.g., acompound valve seat) that comprises multiple materials in multipleregions. For example, such valve seats may include a relatively lowerstrength material (e.g., a material exhibiting a lower hardness) that ispositioned adjacent a valve member (e.g., a ball element) and arelatively higher strength material (e.g., a material exhibiting arelatively higher hardness) that supports the lower strength material(e.g., under a higher loading scenario) and that may be positionedbetween the lower strength material and a body of the valve. In someembodiments, the valve seat may comprise one or more sections (e.g., twoseparable, distinct pieces or elements) that each comprise one of thehigher or lower strength materials and that are utilized in unison todefine the valve seat. In additional embodiments, the valve seat may beformed as a single section with multiple material regions or may includemore than two separate, distinct pieces or elements.

FIG. 1 illustrates a cross-sectional view of a valve 100 (e.g., a ballvalve) including one or more valve seats 112 in the closed position. Theball valve 100 may include a valve member (e.g., ball 102, obstructor,etc.) movably positioned (e.g., floating or mounted) in a valve body 104(e.g., including a central housing with two end caps) to control fluidflow through the valve 100. The valve body 104 may define a conduit 106(e.g., path, passage, port, etc.) through the valve body 104. The ball102 may include a port 108 (e.g., hole, path, passage, etc.) through theball 102. A stem 110 may extend through the valve body 104 and beoperatively coupled to the ball 102. The ball 102 may be configured toselectively inhibit (e.g., obstruct, at least partially inhibit,substantially stop, substantially prevent, etc.) fluid flow through theball valve 100 when the ball 102 is in a closed position (e.g.,positioned such that the port 108 is not aligned with the conduit 106),as illustrated in FIG. 1. The stem 110 may cause the ball to rotatebetween the closed position and an open position (e.g., wherein the ball102 is positioned such that the port 108 is aligned with the conduit106, as shown in FIG. 2).

The seats 112 (e.g., seal, annular ring, etc.) may be positioned withinthe valve body 104 where the ball 102 and the conduit 106 meet. Eachvalve seat 112 forms a substantially fluid-tight seal through engagementwith portions of the valve 100, for example, with the valve member orball 102 and the valve body 104. The seats 112 may at least partially orsubstantially entirely inhibit flow of fluid around the ball valve 100when the ball 102 is in a closed position and/or an open position bydefining one or more seals between the ball 102 and the valve body 104.

The ball 102 may rest adjacent to and/or against the seats 112. Theseats 112 may be annular (e.g., ring-shaped, substantially circular,etc.). The seats 112 may be configured to form a seal between the ball102 and the valve body 104. In some embodiments, the seats 112 may havea complementary shape to the ball 102. For example, the seats 112 mayexhibit a conical shape (e.g., frustoconical) with an angled innersurface. In some embodiments, the seats 112 may have a complex shape(e.g., an at least partially arcuate shaped cross section) such as ahemispherical slice configured to complement a spherical shape of theball 102 (e.g., having substantially the same radius).

As depicted, one or more of the seats 112 may be formed in at least tworegions or sections. A first region 114 may be at least partially formedfrom a first material (e.g., substantially all or an entirety of thefirst region 114 may comprise the first material) and a second region116 may be at least partially formed from a second material (e.g.,substantially all or an entirety of the second region 116 may comprisethe second material). In some embodiments, the first material and thesecond material may be different materials (e.g., having differingmaterial properties). In some embodiments, the first material may be asofter or relatively more flexible material than the second material.

For example, the first material or an entirety of the first region 114may have a relatively low durometer indicating the relatively lowhardness of the material as compared to other relatively stiffer (e.g.,rigid) polymers or other types of materials. The first material may havea hardness (e.g., durometer) less than about 100 on the Rockwell Rscale, such as less than about 90 on the Rockwell R scale, less thanabout 75 on the Rockwell R scale, less than about 60 on the Rockwell Rscale, and greater than 50 on the Rockwell R scale (e.g., between on theRockwell R scale 50 and 60, 55 and 65, 60 and 70, 55 and 80, 50 and 90,etc.). The second material or an entirety of the second region 116 mayhave a hardness (e.g., durometer) greater than about 90 on the RockwellR scale, such as greater than about 100 on the Rockwell R scale, greaterthan about 110 on the Rockwell R scale, greater than about 120 on theRockwell R scale, greater than about 130 on the Rockwell R scale, andless than about 150 on the Rockwell R scale (e.g., between on theRockwell R scale 90 and 140, 100 and 130, 110 and 130, 115 and 125, 90and 150, etc.).

By way of further example, the first region 114 may be formed from amaterial having a type A Shore hardness of less than 100 (e.g., between80 and 100, 90 and 100, 70 and 100) and the second region 116 may beformed from a material having a type D Shore hardness of between 75 and100 (e.g., between 80 and 100, 90 and 100).

In some embodiments, the first material (e.g., an entirety of the firstregion 114) may be a flexible material (e.g., resilient material) andthe second material (e.g., an entirety of the second region 116) may bea rigid material. For example, the first material may have a modulus ofelasticity (e.g., Young's modulus) between about 0.1 GPa and about 2GPa, such as between about 0.3 GPa and about 1 GPa, between about 0.4GPa and about 0.9 GPa, or between 0.4 GPa and 0.6 GPa. The secondmaterial may have a modulus of elasticity between about 1.5 GPa andabout 6 GPa, such as between about 2.0 GPa and about 5 GPa, betweenabout 2.5 GPa and about 4 GPa, or between about 3 GPa and about 4 GPa.

In some embodiments, the second material (e.g., an entirety of thesecond region 116) may have a modulus of elasticity that is more thanone times (1×) greater than (e.g., between 1.1× to 5.0× greater, atleast 1.25× greater, at least 1.5× greater, at least 1.75× greater, atleast 2.0× greater, combinations thereof) the modulus of elasticity ofthe first material (e.g., an entirety of the first region 114).

The first material may be a soft or relatively flexible sealingmaterial, such as a polymer (e.g., plastics, elastomers, rubbers, etc.).In some embodiments, the flexible sealing material may be rubber suchas, ethylene propylene diene (EPDM), nitrile rubber (NBR), styrenebutadiene rubber (SBR), silicon rubber, butyl rubber, polybutadiene,etc. In some embodiments, the soft sealing material may be a plasticsuch as, tetrafluoroethylene (TFB), polytetrafluoroethylene (PTFE),modified PTFE (e.g., TFM, DYNEON® TFM 1600, DYNEON® TFM 1700), orreinforced polytetrafluoroethylene (RTFE).

The second material may be a relatively harder or stiffer material suchas, such as a polymer (e.g., plastics) or other harder materials, suchas ceramics, composites, etc. In some embodiments, the second materialmay comprise nylon plastics (e.g., NYLATRON®), polyaryletherketone(e.g., PAEK, polyether ether ketone (PEEK)), polyoxymethylene (e.g.,POM, acetal, polyaceal, polyformaldehyde, DELRIN®, CELCON®, RAMTAL®,DURACON®, KEPITAL®, and HOSTAFORM®), reinforced TFM (e.g., TFM1600+20%GF), carbon filled PTFE, or polychlorotrifluoroethylene (e.g., PCTFB,PTFCE, KEL-F®, etc.).

FIG. 2 illustrates a cross section of the ball valve 100 in an openposition. In the open position, the port 108 through the ball 102 may besubstantially aligned with the conduit 106 through the valve body 104such that fluid may pass through the ball valve 100. In the openposition, the force between the ball 102 and the seat 112 may bereduced. When the ball valve 100 returns to a closed position (FIG. 1),the increase in force between the ball 102 and the seat 112 may beintroduced suddenly such that the impact (e.g., shock, impulse, etc.)absorbed by the seat 112 may be greater than the force that the pressurealone would cause when the ball valve 100 is in a closed position.

The seats 112 may substantially inhibit or limit flow of fluid aroundthe ball valve 100 when the ball 102 is in one or both of the openposition and the closed position by defining a seal between the ball 102and the valve body 104. For example, the seats 112 may act to at leastpartially ensure that a majority or entirety of the fluid flow travelsthrough an intended flow path (e.g., through the ball 102) whileminimizing or entirely preventing fluid from traveling around theoutside of the ball 102 when the ball 102 is in the open position.Likewise, the seats 112 may prevent unwanted fluid flow around the ball102 when in the closed position.

FIG. 3 illustrates an isometric view of a valve seat 300, which may besimilar and include one or more of the features of the other valve seatsdiscussed herein. Referring to FIGS. 1 and 3, the valve seat 300 mayinclude a first seat section (e.g., an insert 302, seat member, firstregion, first section) and a second support section (e.g., an outerhousing 304, support member, second region, second section). The outerhousing 304 may include an outer surface 306 (e.g., lateral or radialextent, outer wall) and an inner surface 308 (e.g., radially innerwall). The outer surface 306 of the outer housing 304 may be positionedadjacent the valve body 104 (e.g., bordering, contacting, securing thehousing 304 against the valve body 104). For example, the outer housing304 may be sized such that an outer diameter of the outer surface 306 issubstantially the same or slightly smaller or even larger than an innerdiameter of the valve body 104 such that the outer housing 304 sitswithin, adjacent to or contacting, the valve body 104 (e.g., whileoptionally forming an interference fit, press fit, friction fit with thevalve body 104).

The outer housing 304 may operate as a spacer providing separationbetween the insert 302 and the valve body 104 while supporting theinsert 302 (e.g., by limiting deformation of the insert 302). Forexample, the outer housing 304 may enable the insert 302 to elasticallydeform (e.g., to conform to the shape of the ball 102 under loading)without failing (e.g., breaking the seal between the valve seat 300 andthe valve body 104), for example, by deforming to an extent that theinsert 302 no longer makes sealing contact with the ball 102.

The insert 302 may be at least partially disposed within the outerhousing 304. For example, the insert 302 may be disposed such that anentirety of a width 303 (e.g., an axial extent) of the insert 302 isreceived within the width 305 (e.g., an axial extent) of the outerhousing 304. In some embodiments, only a portion of the width 303 of theinsert 302 may be disposed within the outer housing 304, such that aportion of the insert 302 protrudes in an axial direction from one ormore axial sides of the outer housing 304.

In some embodiments, the insert 302 may be at least partially surrounded(e.g., radially surrounded) by the outer housing 304, such that anentirety of the insert 302 is positioned radially within the outerhousing 304. For example, the insert 302 may exhibit a diameter thatfits within a larger diameter of the outer housing 304. In additionalembodiments, at least a portion of the insert 302 may extend beyond anouter portion of the outer housing 304.

The insert 302 may be fitted within the outer housing 304. For example,the insert 302 may be secured to the inner surface 308 of the outerhousing 304 through an interference fit (e.g., press fit, friction fit,etc.). In some embodiments, the insert 302 may be otherwise secured tothe inner surface 308 of the outer housing 304, for example, with anadhesive (e.g., epoxy, glue, adhesive strips, etc.). or through otherknown processes such as, plastic welding, friction welding, chemicalwelding, soldering, intersecting threads, etc.

The insert 302 may include a seating surface 310 positioned proximatethe ball 102 and configured to contact and/or form a seal between theinsert 302 and the ball 102. The seating surface 310 may besubstantially flat or planar and angled (e.g., relative to the axis ofthe seat 300) such that a leading end 312 has a larger diameter than atrailing end 314 (e.g., the seating surface 310 exhibits a frustoconicalshape). In some embodiments, the seating surface 310 may have acomplementary radius to the portion of the ball 102 which the seatingsurface 310 contacts (e.g., substantially the same radius as thecontacting portion of the ball 102). In some embodiments, the seatingsurface 310 may be formed from multiple intersectingfrustoconical-shaped surfaces.

The outer housing 304 may include a secondary seating surface 316. Forexample, the secondary seating surface 316 may provide another sealbetween the valve seat 300 and the ball 102 if the seating surface 310of the insert 302 fails to form a seal or in addition to the seatingsurface 310 of the insert 302. As depicted, the secondary seatingsurface 316 may exhibit substantially the same shape as the seatingsurface 310 of the insert 302 (e.g., a frustoconical shape configured toengage with a larger diameter portion of the ball 102). In someembodiments, the secondary seating surface 316 may be formed such thatthe ball 102 does not contact the secondary seating surface 316 unlessor until a selected level of force (e.g., fluid flow, pressure, etc.) isreached. In some embodiments, the secondary seating surface 316 may beformed such that the ball 102 does not contact the secondary seatingsurface 316 unless or until the insert 302 becomes worn, damaged (e.g.,plastically deformed), or otherwise cannot form a seal against the ball102.

The outer housing 304 may be formed from a harder material than theinsert 302 as described above with respect to the first region 114 andthe second region 116 of FIG. 1. A softer material may require lessforce to form a seal. For example, the force required to elasticallydeform the insert 302 between the ball 102 and the outer housing 304 maybe relatively lower. The reduced force may allow the ball 102 to movemore easily against the insert 302. However, the softer material on theinsert 302 alone may lack the strength to withstand high pressurespresent within the valve 100, thereby potentially damaging the insert302 if used alone. The harder material of the outer housing 304 maycompensate for the reduced strength of the insert 302 and support theinsert 302 (and the ball 102) in environments involving relativelyhigher forces and pressures. Such hard and soft materials may be similarto the first and second materials described above with respect to FIG.1.

FIG. 4 illustrates the valve seat 300 of FIG. 3 in an exploded view.Referring to FIGS. 1 and 4, the outer housing 304 may include a recess320 defined by the inner surface 308 of the outer housing 304 and ashelf 322 (e.g., ridge, retention, stop, etc.). The insert 302 may besecured within the recess 320 such that the trailing end 314 of theinsert 302 rests against the shelf 322. In some embodiments, the insert302 may be secured to or in the outer housing 304 as described abovewith respect to FIG. 3. In some embodiments, the pressure provided bythe ball 102 in the valve assembly may maintain the insert 302 inposition. The pressure creating a seal between the ball 102 and theseating surface 310 of the insert 302 may similarly create a sealbetween an outer portion 324 of the insert 302 and the inner surface 308of the outer housing 304 and/or between the trailing end 314 of theinsert 302 and the shelf 322 of the housing 304.

In some embodiments, an intermediary seal may be included in the valveseat 300. The intermediary seal may be another annular ring formed froma polymeric material. In some embodiments, the intermediary seal may beformed from a material that is harder than the insert 302 and softerthan the outer housing 304. In some embodiments, the intermediary sealmay be formed from an elastomeric material (e.g., rubber) such as, anO-ring or sealing strip. The intermediary seal may be configured toconform to differences in geometry between the outer portion 324 of theinsert 302 and the inner surface 308 of the outer housing 304.

FIG. 5 illustrates a cross-sectional view of a valve seat 500, which maybe similar and include one or more of the features of the other valveseats discussed herein. Referring to FIGS. 1 and 5, the valve seat 500may include an insert 502 and an outer housing 504. The insert 502 maybe disposed within a recess 520 in the outer housing 504 where atrailing end 514 of the insert 502 rests against a shelf 522 and anouter radial portion 524 of the insert 502 is positioned adjacent orrests against an inner surface 508 of the outer housing 504. Asdescribed above with respect to FIGS. 3 and 4, the insert 502 may beformed from a soft sealing material configured to form a seal betweenthe insert 502 and the ball 102. The outer housing 504 may likewise beformed from a harder sealing material, as described above. Therelatively harder sealing material of the outer housing 504 may beconfigured to form a seal between the outer housing 504 and the ball102. In some embodiments, a seating surface 510 of the insert 502 may beconfigured to form a seal with the ball 102. For example, a secondaryseating surface 516 on the outer housing 504 may define a seal betweenthe outer housing 504 and the ball 102 in addition to the seal formedwith the insert 502 or when the seating surface 510 of the insert 502fails to form a seal.

In some embodiments, the insert 502 may include an end portion (e.g., aleading end 512) that spaces the seating surface 510 from a portion ofthe outer housing 504. For example, the leading end 512 may define asurface aligned in an axial direction of the seat 500 that spaces theseating surface 510 from the outer housing 504 (e.g., the sealingsurface 516 of the outer housing 504) and may act to at least partiallyalign the seating surfaces 510, 516 in a substantially similar angledplane.

In some embodiments, the insert 502 may include another end portion(e.g., the trailing end 514) that spaces the seating surface 510 fromanother portion of the outer housing 504 (e.g., the shelf 522).

Although the outer housing 502 may at least partially be utilized toseal against the valve body 104, the harder sealing material of theouter housing 504 may require a higher amount of force to form a sealthan the soft sealing material of the insert 502. However, the hardersealing material of the outer housing 504 may withstand forces due tohigher pressures better than the soft sealing material of the insert502. In some embodiments, the seating surface 510 of the insert 502 mayform a seal against the ball 102 while the secondary seating surface 516of the outer housing 504 may support the ball 102 (and the insert 502)in, for example, high pressure applications (e.g., to counteract forcesapplied to the seat 500 with the ball 102).

Similar to that discussed above, the outer housing 504 may include anouter surface 506 (e.g., lateral or radial extent, outer wall) that ispositioned adjacent a radial portion of the valve body 104 (e.g.,bordering, contacting, securing the housing 504 against the valve body104). The outer housing 504 may include an end surface 507 (e.g., anaxial end, an axial outer wall) that is positioned adjacent an axialportion (e.g., an end cap) of the valve body 104 (e.g., bordering,contacting, securing the housing 504 against a portion of the valve body104).

In some embodiments, the outer housing 504 may include a sealing element530 (e.g., outer body seal) positioned between the outer housing 504 andthe valve body 104 to provide a seal between the outer housing 504 andvalve body 104. For example, the seat 500 may provide a seal between theball 102 and the valve body 104 with (e.g., by elastically deforming)both the insert 502 and the sealing element 530.

As depicted, the outer housing 504 may include a groove 532 (e.g., slot,recess, etc.) configured to retain the sealing element 530. The sealingelement 530 may be at least partially (e.g., partially, substantially,etc.) disposed within the groove 532 at chamfered surface between theouter surface 506 ad the end surface 507 of the outer housing 504. Insome embodiments, the sealing element 530 may be formed fromsubstantially similar materials to the insert 502. For example, thematerials of the sealing element 530 and the insert 502 may be selectedto elastically deform at substantially the same level of force in orderto define the seal in the valve 100. For example, the sealing element530 may be formed from a polymer material, for example, an elastomericmaterial, such as rubber (e.g., ethylene propylene diene (EPDM), nitrilerubber (NBR), styrene butadiene rubber (SBR), silicon rubber, butylrubber, polybutadiene, etc.), neoprene (e.g., polychloroprene,pc-rubber, etc.), polytetrafluoroethylene (PTFE), or polyurethane. Insome embodiments, the sealing element 530 may be an O-ring (e.g., with acircular cross section), a D-ring (e.g., having at least one flat side),or an annular ring with another geometric cross section (e.g., oval,ellipsis, parabolic, square, rectangular, triangle, pentagon, hexagon,octagon, etc.) or an asymmetric cross section.

The sealing element 530 may create and/or maintain a seal between thevalve seat 500 and the valve body 104. The sealing element 530 mayoperate as a primary seal substantially inhibiting (e.g., at leastpartially inhibiting, stopping, preventing, etc.) fluid from passingbetween the valve seat 500 (e.g., the outer housing 504) and the valvebody 104 (e.g., around an outer portion of the valve seat 500). In someembodiments, the sealing element 530 may operate as a secondary (e.g.,backup, fail-safe, etc.) seal to prevent fluid from passing between thevalve seat 500 and the valve body 104 should another seal (e.g., a sealprovided by one or more portions of the outer housing 504) between theouter housing 504 and the valve body 104 fail.

FIG. 6 illustrates a cross-sectional view of a valve seat 600, which maybe similar and include one or more of the features of the other valveseats discussed herein. Referring to FIGS. 1 and 6, a portion of anouter housing 604 (e.g., a trailing surface 607, such as an axiallyouter surface) may be configured to define a seal between the valve seat600 and the valve body 104. As depicted, a sealing element 630 may bepositioned between the outer housing 604 and the valve body 104. Forexample, the outer housing 604 may include a slot 632 (e.g., groove,recess, etc.) defined in the trailing surface 607 configured to retainthe sealing element 630. The sealing element 630 may be at leastpartially (e.g., partially, substantially, etc.) disposed within theslot 632. In some embodiments, the sealing element 630 may be formedfrom a relatively softer polymer or elastomeric material similar to thesealing element 530 described above with respect to FIG. 5. As depicted,the sealing element 630 may be at least one sealing strip (e.g.,substantially flat annular ring). The sealing element 630 may have awidth 634 that is substantially greater than a height 636 of the sealingelement 630.

As depicted, the sealing element 630 may be positioned between thetrailing surface 607 of the outer housing 604 and the valve body 104. Insome embodiments, the sealing element 630 may be positioned between theouter surface 606 of the outer housing 604 and the valve body 104 or atan interface between the outer surface 606 and the trailing surface 607.

FIG. 7 illustrates a cross-sectional view of a valve seat 700, which maybe similar and include one or more of the features of the other valveseats discussed herein. Referring to FIGS. 1 and 7, a portion of anouter housing 704 (e.g., a trailing surface 707, such as an axiallyouter surface) may be configured to define a seal between the valve seat700 and the valve body 104. As depicted, one or more sealing elements730 may be positioned between the outer housing 704 and the valve body104. For example, the outer housing 704 may include one or more slots732 (e.g., groove, recess, etc.) defined in the trailing surface 707configured to retain the one or more sealing elements 730. The one ormore sealing elements 730 may be at least partially (e.g., partially,substantially, etc.) disposed within the one or more slots 732. In someembodiments, the one or more sealing elements 730 may be formed from arelatively softer polymer or elastomeric material similar to the sealingelement 530 described above with respect to FIG. 5.

As depicted, the one or more sealing elements 730 may be at least one ofan annular sealing ring as described above with respect to FIG. 5 or asealing strip as described above with respect to FIG. 6. In someembodiments, the one or more sealing elements 730 may include at leasttwo sealing elements 730 comprising annular sealing rings and/or sealingstrips.

In some embodiments, the one or more sealing elements 730 may bepositioned between a trailing surface 707 of the outer housing 704 andthe valve body 104. In some embodiments, the one or more sealingelements 730 may be positioned between the outer surface 706 of theouter housing 704 and the valve body 104 or at an interface between theouter surface 706 and the trailing surface 707. In some embodiments, theone or more sealing elements 730 may be positioned on different surfacesof the outer housing 704, such as those discussed above.

The embodiments of the present disclosure may provide valve seats havinga relatively softer seat for contacting the valve member, which mayprovide low friction, lower required sealing forces, lower requiredamounts of torque during actuation, and/or relatively higher chemicalresistance. The valve seat also provides a support region having ahigher strength (e.g., stiffer) material having a greater resilience tohigh loads and/or high pressure/temperature than a softer seat. Such acombination or compound seat may be ideally suited to applicationsinvolving high pressure and/or high temperature, along with high loadsor shock loading.

Valve seats according to embodiments of the present disclosure mayfurther provide support in high pressure systems (e.g., including highpressure fluids and/or shock loading scenarios) while maintaining sealsrequiring less force to rotate the ball of a ball valve. In highpressure systems, valve seats of soft materials may fail due todeformation, fatigue, or other failures as a result of the large forcesassociated with high pressures. The higher strength materials used inhigh pressure systems to compensate for the high pressures may requiremuch greater forces (e.g., torque) to rotate the ball of the ball valveagainst the seat. The high forces may require more expensive andcumbersome actuators to move the valves. The embodiments of the presentdisclosure may enable soft seat materials to be used in high pressureapplications allowing for a reduction in the amount of torque requiredto rotate the ball of the ball valve while maintaining the strengthrequired to withstand the large forces associated with the highpressures.

While the present disclosure has been described herein with respect tocertain illustrated embodiments, those of ordinary skill in the art willrecognize and appreciate that it is not so limited. Rather, manyadditions, deletions, and modifications to the illustrated embodimentsmay be made without departing from the scope of the disclosure ashereinafter claimed, including legal equivalents thereof. In addition,features from one embodiment may be combined with features of anotherembodiment while still being encompassed within the scope of thedisclosure as contemplated by the inventor.

What is claimed is:
 1. A valve seat comprising: an insert comprising afirst polymer material, the insert configured to be positioned proximateand to contact a valve member and define a portion of a seal between thevalve member and a valve body in which the valve member is positioned;and an outer housing comprising a second polymer material, at least aportion of the insert is configured to be positioned within the outerhousing, the outer housing configured to be positioned between theinsert and the valve body to define another portion of the seal betweenthe valve member and the valve body, wherein the second polymer materialof the outer housing exhibit a hardness that is greater than a hardnessof the first polymer material of the insert.
 2. The valve seat of claim1, wherein an entirety of the insert comprises the first polymermaterial, and wherein an entirety of the outer housing comprises thesecond polymer material.
 3. The valve seat of claim 1, wherein the outerhousing comprises a recess, and wherein the insert is received in therecess.
 4. The valve seat of claim 3, wherein an entirety of an axialextent of the insert is received within an axial extent of a portion ofthe outer housing defining the recess.
 5. The valve seat of claim 1,wherein the first polymer material has a Rockwell R scale hardness lessthan 100 and greater than
 50. 6. The valve seat of claim 5, wherein thesecond polymer material has a Rockwell R scale hardness greater than 100and less than
 150. 7. The valve seat of claim 1, further comprising anouter body seal positioned at an outer lateral extent of the outerhousing, the outer body seal configured to at least partially defineanother portion of the seal between the valve member and the valve body.8. The valve seat of claim 7, wherein the outer body seal and the insertcomprise substantially similar materials configured to elasticallydeform at substantial the same level of force.
 9. The valve seat ofclaim 7, wherein the outer housing comprises an annular grooveconfigured to receive a portion of the outer body seal in the annulargroove.
 10. A valve assembly comprising: a valve body comprising atleast one port; a valve member positioned within the valve body andconfigured to selectively enable fluid to pass through the at least oneport in the valve body; and at least one valve seat comprising: a seatmember comprising a polymer material, the seat member positionedadjacent and configured to seal against the valve member; and a supportmember comprising another polymer material, the support memberpositioned between the seat member and the valve body and configured toseal against the valve body.
 11. The valve assembly of claim 10, whereinthe valve assembly comprises a ball valve and the valve member comprisesa rotatable ball positioned in the valve body.
 12. The valve assembly ofclaim 10, wherein the another polymer material of the support memberexhibits a hardness that is greater than a hardness of the polymermaterial of the seat member.
 13. The valve assembly of claim 12, whereinthe seat member has a Rockwell R scale hardness less than 70 and greaterthan
 50. 14. The valve assembly of claim 13, wherein: the seat membercomprises a material selected from the group consisting oftetrafluoroethylene, polytetrafluoroethylene, modifiedpolytetrafluoroethylene, and reinforced polytetrafluoroethylene; and thesupport member comprises a material selected from the group consistingof nylon plastics, polyaryletherketone, polyoxymethylene, carbon filledPTFE, and polychlorotrifluoroethylene.
 15. The valve assembly of claim10, wherein the seat member is received within a portion of the supportmember.
 16. The valve assembly of claim 15, wherein the support memberspaces and separates the seat member from the valve body.
 17. The valveassembly of claim 10, wherein the support member comprises a separatebody sealing member configured to contact and seal against the valvebody.
 18. The valve assembly of claim 17, wherein the body sealingmember comprises a material having a hardness that is substantiallysimilar to a hardness of the polymer material of the seat member.
 19. Amethod of providing a seal in a ball valve, the method comprising:positioning a first section of a seat comprising a first polymermaterial adjacent a movable ball of the ball valve; positioning a secondsection of the seat comprising a second polymer material adjacent a bodyof the ball valve; and forcing the movable ball into the seat to form aseal between the movable ball and the valve body with the seat.
 20. Themethod of claim 19, further comprising deforming a portion of the secondsection of the seat comprising a third polymer material into the valvebody.